Meter construction



United States Patent [72] Inventor William E. Engelhard Apalachin, NewYork [21 Appl. No. 727,260

[22] Filed May 7, 1968 [45] Patented Sept. 22, 1970 [73] AssigneePyro-Serv Instruments, Inc.

North Arlington, New Jersey a corporation of New Jersey [54] METERCONSTRUCTION 4 Claims, 3 Drawing Figs.

116/129 Gl2b 3/02 [50] 116/129.

[56] References Cited UNITED STATES PATENTS 3,087,380 4/1963 Greger eta1. 324/157X 3,254,533 6/1966 Tongret 73/362(R)UX 3,403,656 10/1968Barry et al. 116/129 Primary Examiner-S. Clement Swisher AssistantExaminer-Frederick Shoon Attorney-Sommers and Sommers ABSTRACT: A meterhaving a needle movable over a scale and a needle retaining device toprevent movement of the needle. The needle retaining device includes awire which may be moved into intimate engagement with the needle topress the needle against the meter face. The wire is connected to arotatable shaft which is biased so that the needle is normallyimmobilized. The meter further includes a lever for rotating said shaftto release the needle to take a reading.

Patented Sept. 22, 1970 FIGS INVENTOR.

William E. Engelhard ATTORNEYS METER CONSTRUCTION This invention relatesgenerally to an improved meter construction and, more particularly,pertains to a meter construction in which the needle may be selectivelyimmobilized to retain the needle position on an associated scale.

Portable hand-held measuring devices usually are specifically adaptedfor use in the field rather than for use in a laboratory or the like.Hence, the portable instrument may be moved into an ideal measuringposition but one in which an accurate reading becomes extremelydifficult. For example, the device may have to be held at arms length toobtain an accurate measurement of a variable quantity. Thus, althoughthe particular measurement may be accurate, the actual reading of theinstrument will, at best, be an approximation which depends on theeyesight of the instruments operator. The operator must look directlythrough dark glasses at the molten metal in order to control the tipimmersion of the meter. Needle retention allows the operator to take areading and then, after his eyes have grown accustomed to the light, tomove away from the heat and glare to view the reading accurately.

Accordingly, an object of the present invention is to provide a meterfor a measuring device which retains the reading of the meter.

A more specific object is to provide a meter having means to retain amovable needle in an indicating position.

Another object and feature resides in the novel details of constructionwhich provide a. meter of the type described which is rugged, dependableand economic to fabricate.

Accordingly, a meter constructed in accordance with the presentinvention includes a front face having a scale thereon. A needle isadapted to move over the scale in response to the value of the quantityto be measured. Retaining means is provided to prevent movement of theneedle. The retaining means includes a rotatable shaft having needleconstraining means connected thereto which is adapted to be moved intoengagement with the needle upon movement of the shaft to a firstposition to press said needle against the face thereby to preventmovement of the needle. Operating means is included for moving saidshaft to a second position to release the needle for movement. Biasingmeans biases the shaft to the first position so that the needle isnormally immobilized.

Other features and advantages of the present invention will become moreapparent from a consideration of the following detailed description whentaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front elevational view, with parts broken away, of ameasuring device incorporating a meter constructed in accordance withthe present invention;

FIG. 2 is a side elevational view thereof; and

FIG. 3 is a fragmentary cross-sectional view thereof.

FIGS. 1 and 2 illustrate a portable hand-held measuring device,designated generally by the reference numeral 10, which incorporates ameter 12 constructed according to the present invention. While the meter12 may be used in conjunction with any instrument adapted to measure thevalue of a desired quantity, for purposes of the present invention, themeter 12 will be described as a temperature indicating meter. Hence, thedevice will be described as a pyrometer. However, it is emphasized thatthis is by way of illustration only and is not to beiinterpreted as alimitation of the invention.

The pyrometer 10 includes a housing 14 having a front wall 16. Providedin the front wall 16 is an opening 18 in which is positioned atransparent member 19 (such as glass) through which the scale 20 on theface 21 of the meter 12 is visible. In other words, the meter 12 isreceived within the housing 14. The meter 12 is of the type whichincludes a needle 22, one end of which is pivotally connected to themeter movement 24.

Retaining means is provided to prevent movement of the needle 22. Morespecifically, spaced loops 26 are provided which are affixed to themeter face 21. Extending through the loops 26 and being rotatable withrespect thereto is a shaft 28. The shaft 28 is spaced below the loweredge of the opening 18. The shaft 28 includes tapering end portions 30which extend upwardly toward the scale 20 and outwardly toward the sidewalls of the housing 14. The spacing between the ends of the endportions 30 is such that if the end portions 30 were extended, the scale20 would be positioned therebetween. Connected between the ends of theend portions 30 is a needle constraining means in the form of a wire 32.

The relative spacing of the parts in the retaining means is shown inFIG. 3. The spacing between the-wire 32 and the scale face 21 must betightly maintained and controlled across the entire length of the wire32 to avoid crunching the needle 22 against the scale face 21 or missingthe needle 32 at the high spot of the wire 32. In order to accomplishthese objectives the space is controlled by using a wire 32 of suitablediameter and spring properties. The spring properties are used to keepthe clamping wire straight and also to allow the high end of wire 32 tomove down towards the scale 21. The clamping wire is stretched acrossand soldered onto a notch at each end portion 30 of the shaft 28, theend portions 30 having been pinched to enable soldering of the wire tothe notches and then released to tension the wire 32. The depth of thenotch can be made to exactly match the wire clearance. Any slightunevenness of the end portion 30 are taken care of on being depressed,by the torquing action of the compressible member 36 and the lever 34.

To be more specific, when the shaft 28 is rotated in thecounter-clockwise direct'bn, as seen looking from the left in FIG. 1,the wire 32 is moved into intimate contact with the needle 22 to pressthe needle enough to hold but not against the meter face 21.Accordingly, the meter needle 22 will be immobilized or prevented fromchanging its position. However, when the shaft is rotated in theopposite direction the wire 32 is moved away from the needle 22 therebyto free the needle for movement over the length of the scale 20 inresponse to the current flow.

Movement of the shaft 28 between needle constraining and needle movingpositions is effected by operating means which includes a lever 34, oneend of which is rigidly connected to the shaft 28. When the other end ofthe lever 34 is moved toward the meter face 21, the shaft 28 is rotatedto the position wherein the needle has freedom of movement. Acompressible member 36, such as a spring, or a foam rubber pad tocontrol grounding or static problems, or the like, is connected to themeter face and is adapted to engage the under surface of the lever 34 tobias the shaft 28 to the needle constraining position to immobilize theneedle.

The operating means further includes a plunger 38 slidably receivedthrough an appropriate bore in the front wall 16 which is positioned toengage the free end of the lever 34. Movement of the plunger 38 inwardlycauses the free end of the lever 34 to move toward the meter face tofree the needle 22 in the manner noted above.

Depending from the housing 14 is a handle 40 having a front surface 42and a rear surface 44. The handle 40 is provided with ribs spacedthroughout its length to facilitate holding the device 10. Extendingoutwardly from the rear surface 44 of the handle 40 is a depressiblepush-button 46 (FIG. 2) which is adapted to cause energization of themeter when it is depressed. For example, depression of the push-button46 may close a switch which connects the meter movement 24 with anenergizing circuit.

As shown clearly in FIG. 2, the push-button 46 and the plunger 38 aresized and positioned to be operated by one hand thereby freeing theother hand of the operator. More particularly, the handle 40 is graspedby a hand as shown by the dashed lines H. The fingers wrap around thehandle with the forefinger resting on the push-button 46. The thumbrests on the plunger 38.

As noted above, in this illustrative embodiment the device 10 is apyrometer. Accordingly, in operation a thermocouple 48 is placed incontact with the object whose temperature is to be measured. Thereafterthe handle 40 is grasped by the operator in the manner noted above andthe push-button 46 and the plunger 38 both are depressed. This actionenergizes the meter movement 24 and releases the needle 22 for movement.Thus, the needle 22 moves to a position indicative of the temperature ofthe object. The plunger 38 is then released to allow the shaft 28 torotate to the needle constraining position under the biasing influenceof the member 36. Hence, the needle 22 will be locked" in position andwill not be able to move even though the device is moved or otherwisejostled. The push-button 46 thereafter is released.

Accordingly, the operator may then remove the thermocouple from theobject and move the device 10 to read the meter then or at a later timeor another location more convenient to him or to a position in which themeter 12 easily is readable. In other words, since the needle is fixedin position it is not necessary to read the meter while the device isstill connected to the measured object. Thus, the device 10 may be movedto a position wherein the operator may take an accurate reading of themeter.

Hence, a meter has been disclosed which is simple to fabricate andoperate and which maintains the needle in position so that accuratereadings may be taken regardless of the orientation of the device duringthe measuring operation.

While a preferred embodiment of the invention has been disclosed it willbecome obvious that numerous omissions, changes and additions may bemade in such embodiment without departing from the spirit and scope ofthe present invention.

l claim:

1. A meter having a scale thereon:

a needle mounted for movement over said scale;

retaining means for preventing movement of said needle, said retainingmeans comprising a shaft movably mounted in said meter in spacedrelationto said scale, spaced outturned ends on said shaft; a flexiblemember secured at its ends to the out-turned ends of the shaft and heldtaut between said out-turned ends;

said flexible member being adapted, on movement of the shaft to a firstposition, to be thereby moved into engagement with said needle, toengage the needle; and

means for biasing said shaft to said first position to so engage saidneedle. 2. In a meter as set forth in claim 1, a lever connected at oneend to said shaft to move said shaft from said first position and thusrelease said needle from said flexible member.

3. In a meter as in claim 2, said shaft biasing means comprising acompressible member engaging said lever to move said shaft to said firstposition.

4. in a meter as in claim 3, a depressible meter operating buttonmovably mounted in said meter and extending from the meter, adapted tobe depressed by the finger to energize said meter;

and means for engaging said lever mounted in said meter at a pointopposite the button: and

said means for engaging the lever and said meter button being adapted tobe operated by one hand to simultaneously energize said meter andrelease said needle for movement.

